Quote:
Originally Posted by ericwoo
Ok this is what I found out with the leak down test. Air is coming out of the valve cover breather on the Driver side but not the Passenger side. From what I am reading, that would be worn piston rings, correct?
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Maybe. I don't understand why one side of the engine would have blowby pressure but the other side doesn't. However, "air coming out the valve cover" could be TOTALLY NORMAL. Kinda depends on the
volume of blowby--there's always going to be some.
What are the gauges on the leakdown tester showing? Do you have a Master Orifice to provide some feedback on what is acceptable? If not, you need to test some known-good cylinders of about the same bore diameter.
You don't have "breathers" on BOTH valve covers...right? Is there a properly-functioning PCV system on this engine?
Quote:
Originally Posted by ericwoo
A while back, I do remember seeing surface rust on steel components when I took off the valve cover. I was thinking a little bit of water must have seeped through the valve cover gasket when I degreased the engine compartment. I wonder if surface rust developed on the piston rings and cylinder, ruining it. However, I do not remember the engine producing much more power before washing the engine either.
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One of the main byproducts of combustion is water vapor. Blowby puts that water vapor into the crankcase.
If the engine is running, there's no "surface rust" on the cylinder walls.
Quote:
Originally Posted by ericwoo
I will never understand the engineering of Pontiacs poor valve cover design with the 4 bolts. I always had issues with sealing them to prevent oil coming out.
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Bolts cost money. So do drilled and tapped holes. You want GM big-shots to give up their bonuses so you don't have oil leaks?